Story Start: What is that?

Both sat silent, listening. Jules heard nothing over the fan of the computer. She said, “Let’s get back to it. This paper isn’t going to write itself.”

Just then Bill jumped out of his chair. “Something’s scratching on the front door!” he shouted as he ran out of the room, returning seconds later with a baseball bat in his hands.

“What the hell, Bill,” Jules said. “You’re starting to freak me out.”

Bill did not answer but headed to the front door. With a sigh, Jules got up and followed. She saw Bill pause with his hand on the doorknob. Then she heard it. A slow, deliberate scratching sound like something sharp scraping along the wood of the door. Before she could say anything, Bill pulled the door open. He screamed. Jules gasped.